Essentially planar lighting system

ABSTRACT

A lighting system includes an essentially planar panel assembly configured to transmit light. At least one light source is positioned about the periphery of the essentially planar panel assembly and configured to direct light into the essentially planar panel assembly and essentially along a longitudinal axis of the essentially planar panel assembly.

TECHNICAL FIELD

This disclosure relates to lighting systems and, more particularly, toessentially planar light systems.

BACKGROUND

Light fixtures may use various types of lighting elements, such asincandescent elements, fluorescent elements, and light emitting diodeelements. Light fixtures maybe configured to be mounted in various ways,such as: within suspended ceilings; suspended from traditional ceilings,rigidly affixed to ceilings; and rigidly affixed to walls.

Unfortunately, light fixture employing the above-described lightingelements may be substantially thick (when measured from the lightingsurface inward), thus limiting the manner in which the light fixture maybe utilized.

SUMMARY OF DISCLOSURE

Accordingly to a first aspect of this disclosure, a lighting systemincludes an essentially planar panel assembly configured to transmitlight. At least one light source is positioned about the periphery ofthe essentially planar panel assembly and configured to direct lightinto the essentially planar panel assembly and essentially along alongitudinal axis of the essentially planar panel assembly.

One or more of the following features may be included. The at least onelight source may include at least one light emitting diode assembly. Atleast one driver circuit may energize the at least one light emittingdiode assembly. The lighting system may be configured to fit within asuspended ceiling track assembly. The lighting system may be configuredto be suspended from one of more pendant cable assemblies. A bracketassembly may attach the lighting assembly to a surface. A plate assemblymay be positioned proximate a first surface of the essentially planarpanel assembly and may be configured to reflect at least a portion ofthe light generated by the at least one light source outward through asecond surface of the essentially planar panel assembly. The plateassembly may be constructed of a polished metallic material. Anoptically-polarizing film may be positioned proximate a second surfaceof the essentially planar panel assembly. The essentially planar panelassembly may be constructed, at least in part, of a material chosen fromthe group consisting of: acrylic, glass and polycarbonate. A frameassembly may be positioned about the periphery of the essentially planarpanel assembly, such that the frame assembly may be configured to atleast partially encapsulate at least a portion of the at least one lightsource.

Accordingly to another aspect of this disclosure, a ceiling tileassembly includes an essentially planar panel assembly configured totransmit light and fit within a suspended ceiling track assembly. Atleast one light emitting diode assembly is positioned about theperiphery of the essentially planar panel assembly and configured todirect light into the essentially planar panel assembly and essentiallyalong a longitudinal axis of the essentially planar panel assembly.

One or more of the following features may be included. At least onedriver circuit may energize the at least one light emitting diodeassembly. A plate assembly may be positioned proximate a first surfaceof the essentially planar panel assembly and configured to reflect atleast a portion of the light generated by the at least one lightemitting diode assembly outward through a second surface of theessentially planar panel assembly. The plate assembly may be constructedof a polished metallic material. An optically-polarizing film may bepositioned proximate a second surface of the essentially planar panelassembly. The essentially planar panel assembly may be constructed, atleast in part, of a material chosen from the group consisting of:acrylic, glass, and polycarbonate.

Accordingly to another aspect of this disclosure, a lighting systemincludes an essentially planar panel assembly configured to transmitlight. At least one light emitting diode assembly is positioned aboutthe periphery of the essentially planar panel assembly and configured todirect light into the essentially planar panel assembly and essentiallyalong a longitudinal axis of the essentially planar panel assembly. Aframe assembly is positioned about the periphery of the essentiallyplanar panel assembly, such that the frame assembly is configured to atleast partially encapsulate at least a portion of the at least one lightemitting diode assembly.

One or more of the following features may be included. At least onedriver circuit may energize the at least one light emitting diodeassembly. The plate assembly may be constructed of a polished metallicmaterial.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is perspective view of a suspended ceiling employing anessentially planar lighting system;

FIG. 2 is a diagrammatic view of a wall-mounted essentially planarlighting system and a ceiling mounted essentially planar lightingsystem;

FIG. 3 is a diagrammatic view of an essentially planar lighting systemsuspended from a ceiling;

FIG. 4 is a diagrammatic view of an essentially planar lighting system;

FIG. 5 is a first cross-sectional view of the essentially planarlighting system of FIG. 4;

FIG. 6 is a second cross-sectional view of the essentially planarlighting system of FIG. 4; and

FIG. 7 is a schematic view of a driver circuit for use with theessentially planar lighting system of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, there is shown a first embodiment of lightingsystem 10 that may be configured to be installed within track assembly12 of suspended ceiling 14. Examples of suspended ceiling 14 may includethose manufactured by Armstrong Industries of Lancaster, Pa. Referringalso to FIG. 2, there is shown an alternative embodiment lighting system16 that may be configured to be mounted to ceiling assembly 18 viabracket assembly 20 (which may be coupled to electrical box 22). Analternative embodiment lighting system 24 may be configured to bemounted to a wall assembly 26 via bracket assembly 28 (which may becoupled to electrical box 30). Referring also to FIG. 3, there is shownan alternative embodiment lighting system 32 that may be suspended frommounting plate assembly 34 (which may be coupled to electrical box 36)via one or more pendant cable assemblies 38, 40.

Referring also to FIGS. 4 & 5, there is respectively shown a top viewand a cross-sectional side view (along section line 50) of lightingsystem 10, 16, 24, 32. Lighting system 10, 16, 24, 32 may include anessentially planar panel assembly 52 and one or more light sources 54,56, 58, 60 positioned about the periphery of essentially planar panelassembly 52.

Essentially planar panel assembly 52 may be constructed of a lighttransmitting material, such as a polycarbonate material (e.g., Lexan™ byGeneral Electric of Schenectady, N.Y.), an acrylic material (e.g.,Lucite™ by The DuPont Corporation of Wilmington, Del.), or anotherresin-based material. Alternatively, essentially planar panel assembly52 may be constructed of glass.

Light sources 54, 56, 58, 60 may include one or more light emittingdiodes (e.g., light emitting diodes 62, 64, 66, 68) and any requiredcontrol circuitry (to be discussed below in greater detail). Lightsources 54, 56, 58, 60 may be configured to direct light intoessentially planer planar panel assembly 52 and essentially alonglongitudinal axis 70 of essentially planar panel assembly 52.

For example, the cross-sectional view of lighting system 10, 16, 24, 32is shown to include two light emitting diodes, namely light emittingdiode 72 (which is included within light source 58) and light emittingdiode 74 (which is included within light source 54). In this particularembodiment, light emitting diodes 72, 74 are each shown to direct light76, 78 (respectively) into essentially planer panel assembly 52essentially along longitudinal axis 70.

Referring also to FIG. 6, there is shown a cross-sectional view oflighting system 10, 16, 24, 32 (along section line 80), whichillustrates the longitudinal spacing (x) of the light emitting diodes62, 64, 66, 68 included within light source 60. A typical value for x is0.50 inches. However, this spacing may be increased or decreased to varythe intensity of the light generated by lighting system 10, 16, 24, 32.

As discussed above, essentially planar panel assembly 52 may beconfigured to transmit light. Therefore, while e.g., light emittingdiodes 72, 74 transmit light into essentially planar panel assembly 52essentially along longitudinal axis 70, unless constrained, light willexit essentially planar panel assembly 52 through the upper and lowersurfaces 80, 82 of essentially planar panel assembly 52. Accordingly,when lighting system 10, 16, 24, 32 is configured to provide directlighting 84 (e.g., light in a downward direction for direct illuminationof an object) and indirect lighting 86 (e.g., light in an upwarddirection for reflecting off of e.g., a ceiling for indirectillumination of an object), the upper and lower surfaces 80, 82 ofessentially planar panel assembly 52 may be left uncovered, thusallowing for light (as generated by light emitting diodes 72, 74) toexit essentially planar panel assembly 52 through both upper surface 80(as indirect light 86) and lower surface 82 (as direct light 84).Alternatively, if lighting system 10, 16, 24, 32 is configured to onlyprovide direct light 84 (e.g., light in the downward direction fordirect illumination of an object), plate assembly 88 may be affixed toand/or positioned proximate upper surface 80 of essentially planar panelassembly 52. Further, if lighting system 10, 16, 24, 32 is configured toonly provide indirect light 86 (e.g., light in the upward direction forindirect illumination of an object), plate assembly 88 may be affixed toand/or positioned proximate lower surface 82 of essentially planar panelassembly 52.

Plate assembly 88 may be constructed of an opaque material (e.g., metalor plastic) to prevent the passage of light through upper surface 80(and/or lower surface 82). Additionally, plate assembly 88 may includepolished surface 90 for reflecting light toward lower surface 82 (and/orupper surface 80). For example, plate assembly 88 may be constructed ofpolished aluminum or vacuum-metalized plastic.

Lighting system 10, 16, 24, 32 may include an optically polarizing film92 affixed and/or positioned proximate one or more surfaces ofessentially planar panel assembly 52. An example of optically polarizingfilm 92 is Optical Lighting Film manufactured by 3M of Saint Paul, Minn.

Lighting system 10, 16, 24, 32 may include a frame assembly 94positioned about the periphery of essentially planar panel assembly 52.Frame assembly 94 may be configured to at least partially encapsulate atleast a portion of one or more of light source 54, 56, 58, 60. Forexample, for a square/rectangular essentially planar panel assembly 52,frame assembly 94 maybe be constructed of e.g., four mitered sections96, 98, 100, 102 of aluminum “U” channel.

Referring also to FIG. 7, lighting system 10, 16, 24, 32 may include oneor more driver circuits 104 for receiving a signal 106 from e.g., alight switch (not shown) and selectively energizing one or more of lightsources 54, 56, 58, 60. Driver circuit 104 may include transformer 108for converting the voltage of signal 106 (e.g., 120 VAC, 208 VAC/277VAC) to a voltage usable by the various components of driver circuit104. For example, assume that signal 106 is a 120 VAC signal andtransformer 108 has a 5:1 winding ratio, thus reducing the 120 VACprimary-side signal to a 24 VAC secondary-side signal. Driver circuit104 may include an AC-DC converter 110 for converting the AC signal(e.g., 24 VAC) of the secondary side of transformer 108 to a DC signal(e.g., 24 VDC) usable by the various components of driver circuit 104.Driver circuit 104 may be configured to energize several light emittingdiodes (e.g., diodes 64, 66, 68) in a series configuration.Additionally, driver circuit 104 may include one or more resistivedevices 112 for regulating the current passing through the lightemitting diodes.

For example, assume that AC-DC converter generates a 24 VDC signal thatis provided to diodes 64, 66, 68 and resistive device 112. The voltagerequired to drive a light emitting diode may vary depending on the diodetype and the diode color (e.g., blue and white light emitting diodestypically require higher voltages than e.g., red light emitting diodes).Assume for this example that each of light emitting diodes 64, 66, 68requires a 6 VDC signal to function properly. Accordingly, the followingequation may be used to determine the value of resistive device 112:

$R = \frac{V_{s} - {\sum V_{diodes}}}{i}$

where “i” is the light emitting diode current. Assuming that “i” is 20milliamps, the above equation is populated as follows:

$R = \frac{24 - {\sum 6} + 6 + 6}{0.020}$

Accordingly, setting the value of resistive device 112 to 300 ohmsresults in a voltage drop of 6.00 volts (i.e., 300 ohms×20 milliamps)across resistor 112 while maintaining a 20 milliamp current throughlight emitting diodes 64, 66, 68.

While driver circuit 104 is described above as including transformer108, AC-DC converter 110, and resistor 112 for driving diodes 64, 66,68, this is for illustrative purpose only and is not intended to be alimitation of this disclosure. For example, various switches (not shown)and relays (not shown) may be included within driver circuit 104.

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made. Accordingly, otherimplementations are within the scope of the following claims.

1. A lighting system comprising: an essentially planar panel assemblyconfigured to transmit light; and at least one light source positionedabout the periphery of the essentially planar panel assembly andconfigured to direct light into the essentially planar panel assemblyand essentially along a longitudinal axis of the essentially planarpanel assembly.
 2. The lighting system of claim 1 wherein the at leastone light source includes at least one light emitting diode assembly. 3.The lighting system of claim 2 further comprising: at least one drivercircuit for energizing the at least one light emitting diode assembly.4. The lighting system of claim 1 wherein the lighting system isconfigured to fit within a suspended ceiling track assembly.
 5. Thelighting system of claim 1 wherein the lighting system is configured tobe suspended from one of more pendant cable assemblies.
 6. The lightingsystem of claim 1 further comprising: a bracket assembly for attachingthe lighting assembly to a surface.
 7. The lighting system of claim 1further comprising: a plate assembly positioned proximate a firstsurface of the essentially planar panel assembly and configured toreflect at least a portion of the light generated by the at least onelight source outward through a second surface of the essentially planarpanel assembly.
 8. The lighting system of claim 7 wherein the plateassembly is constructed of a polished metallic material.
 9. The lightingsystem of claim 1 further comprising: an optically-polarizing filmpositioned proximate a second surface of the essentially planar panelassembly.
 10. The lighting system of claim 1 wherein the essentiallyplanar panel assembly is constructed, at least in part, of a materialchosen from the group consisting of: acrylic, glass and polycarbonate.11. The light system of claim 1 further comprising: a frame assemblypositioned about the periphery of the essentially planar panel assembly,wherein the frame assembly is configured to at least partiallyencapsulate at least a portion of the at least one light source.
 12. Aceiling tile assembly comprising: an essentially planar panel assemblyconfigured to transmit light and fit within a suspended ceiling trackassembly; and at least one light emitting diode assembly positionedabout the periphery of the essentially planar panel assembly andconfigured to direct light into the essentially planar panel assemblyand essentially along a longitudinal axis of the essentially planarpanel assembly.
 13. The ceiling tile assembly of claim 12 furthercomprising: at least one driver circuit for energizing the at least onelight emitting diode assembly.
 14. The ceiling tile assembly of claim 12further comprising: a plate assembly positioned proximate a firstsurface of the essentially planar panel assembly and configured toreflect at least a portion of the light generated by the at least onelight emitting diode assembly outward through a second surface of theessentially planar panel assembly.
 15. The ceiling tile assembly ofclaim 14 wherein the plate assembly is constructed of a polishedmetallic material.
 16. The ceiling tile assembly of claim 12 furthercomprising: an optically-polarizing film positioned proximate a secondsurface of the essentially planar panel assembly.
 17. The ceiling tileassembly of claim 12 wherein the essentially planar panel assembly isconstructed, at least in part, of a material chosen from the groupconsisting of: acrylic, glass, and polycarbonate.
 18. A lighting systemcomprising: an essentially planar panel assembly configured to transmitlight; at least one light emitting diode assembly positioned about theperiphery of the essentially planar panel assembly and configured todirect light into the essentially planar panel assembly and essentiallyalong a longitudinal axis of the essentially planar panel assembly; anda frame assembly positioned about the periphery of the essentiallyplanar panel assembly, wherein the frame assembly is configured to atleast partially encapsulate at least a portion of the at least one lightemitting diode assembly.
 19. The lighting system of claim 18 furthercomprising: at least one driver circuit for energizing the at least onelight emitting diode assembly.
 20. The lighting system of claim 18wherein the plate assembly is constructed of a polished metallicmaterial.